Posts Tagged ‘paypal’

The other day I wanted some prettier (tabularized) output and of course someone has already wanted this and of course there are tools for that

bash_completion

This is so frakking cool! I’ve built this little shellscript “vault.sh” which is a simple wrapper script for mounting and unmounting encfs mounts.

It takes two parameters: operation and target, where operation can be one of “lock” and “unlock”, and target—at present—resolves to “thunderbird” (signifying my .thunderbird directory).

Since I intend to expand this with more encrypted directories as I see fit, I don’t want to hard-code that.

What I did want, however, was to be able to auto complete operation and target. So I looked around, and found this post, and although I couldn’t derive enough knowledge from it to solve my particular problem, having multiple levels of completion, the author was gracious enough to provide references to where s/he had found the knowledge (here, here and here). That second link was what did it for me.

And all the magic is happening in the two if-statements. Essentially: if current word (presently half typed and tabbed) is whatever, and this is the second argument to the command, respond with suggestions taken from the variable $second.

Otherwise, if current word is whatever, and this is the first parameter, take suggestions from the variable $first.

Awsum!

awk for great good

Another great use for awk: viewing selected portions of source code. For instance, in Perl, if you just want to view a specific subroutine, without getting distracted by all the other crud, you could do: $ awk '/sub SomeSubName/,/}/' somePerlModule.pm

I needed to iterate over lines in a file, and I needed to use a for loop (well, I probably could have solved it in a myriad other ways, but that’s not the point).

Thanks Luke, updating for clarification: I simplified this problem somewhat to make the post shorter, but the problem in need of solving involved doing some addition across lines, and have the result available after the loop, and for this, I have learned, pipes and the “while read line; do”-pattern isn’t of much help.

So I tell the for loop to do

for line in `cat myfile`; do echo $lines; done

And obviously this doesn’t work, as the IFS variable is set to space, and thus prints out each word on a separate line, instead of printing all the words in one line on lines.

So I think “oh I know, I’ll just change the IFS variable” and try:

IFS="\n"

and this turns out poorly, with the for loop now believing every “n” (and “\”, thanks Luke :)) to be the separator and breaking words on that instead… So I try with single quotes, no joy…

Having approached and passed the point where it is taking me more time to solve this problem rather than solving the problem I was using the loop for, I stop trying and start googling, finding this post.

I haven’t tried it out, but this seems like it could be useful. From that page one could also make their way to one of the projects powering Cube, namely D3, and on that page you can find one or two (or more) interesting diagram types.

And filed under “oh frak! how glad I am that I never got a paypal account!”: